My AINOs have omnipole bass (on the bottom of the box). Yes, it is very difficult to match it with lowmid dipole driver. Distance to boundaries affects low bass and induces frontwall reflections of the dipole backwave. Distance determines the Fq where summations and nulls come, we can see them in the graph (and easier with no smoothing). These are "heavier" than with boxed monopole speakers, but not as bad as with dipole basses

Widely apart, toed-in 30¤ and 1m from front wall is very good. I must also keep my position (head) at least the same 1m from the back-wall! This makes listening distance 1,5m It gives very good sound, but rest of the family doesn't like it . When I have privacy, I take a glass of wine with me to the sweet pot and enjoy Everyday listening must be done with speakers closer to the wall (60cm to dipoles) which is quite acceptable.

Fortunately having a minidsp I can measure and tune it endlessly! MiniDSP 4x10HD box can have 4 preset configurations and I can change them from the panel wheel (no need to connect to computer and run setup program). Frontwall midrange reflections don't have to be eq'd but floor reflection and boundary boost are more constant and easier to eq. So far I haven't saved any roomeq configs, just learning... My indoors-made configs have some floor reflection correction, at my standard 150cm measuring distance Floor/Ceiling Reflection Calculator gives 279Hz (the low-mid driver at 60cm height)

Outdoor measurements are needed for basic driver eq and crossover configuration, but after that I make some indoors PEQ corrections to individual driver responses (based on several measurements), because I listen to these in a room, not outdoors!

Mic position same, position of speaker moved 100cm vs 60cm to fornt wall. Horizontal angle a bit different but not significantly. In both measurements speaker is roughly at 30¤ angle to wall and 5¤ to mic (left speaker of stereo pair, mic at hot spot). behind the speaker is a window, which presents the WORST possible material.

My analysis. The effect on bass is not shown here but it is as loudness boost below 100Hz. The dipole radiation range of AINOs is 200-3000Hz, but I can't see any really big problems with these positions. Cancellations are more significant at 60cm but I can hardly hear any changes except low bass. Obviously nasties increase exponentially as distance gets even smaller.

60cm to front wall is the everyday position. For solo hi-fi sessions I just drag the top-gymnast 42kg AINOs to 100-110cm off the wall! Dipoles should always be toed-in at least 30¤!

Previous vertical offset measurements get a closer look here, without smoothing but different IR windows (postprocessing in REW) Only the lower and upper mid(s) and tweeter playing in these measurements. XO frequencies are 1kHz LR4and 3.3kHz LR4.

Analysis: There is a difference but I can't say which is better overall. MT is better around 3kHz but MTM better around 1kHz.

Distortion with only a single or two upper mid playing, sine at 3150Hz. 36 samples. Please disregard 1kHz and its harmonics, they come from the defective sound card.
Analysis: M is significantly better, mainly because of high odd harmonics of MM

Note: I must perform more distortion measurements after changing the soundcard of UMIK-1. Distortion is a known problem in one batch of them and I got a replacement free. I just haven't changed it yet.

Some thinking processes and distortion tests have guided me to push a little more to the lower limits of NE95 pair and Fountek NeoCD3.5. Middle xo is LR2 again at 800Hz and upper LR4 at 2500hz. Obviously the slopes ease the drivers enogh, There doesn't seem to be a rise in distortion. LR2 between mids gives much better (even) wide angle response than LR4. Lowered tweeter xo should give better vertical off-axis, but I didn't measure it today.

RT and EDT of my room - the effect of closing the light curtains kills the resonation at 2kHz.

It is now obvious to me that the 2kHz undulation I hear is very much this window resonation. These indoor tests don't tell the real behaviour of the speaker! Windows and furniture are rattling too! I haven't fixed the lower mid driver very well - it has vibrations around 100Hz. But overall the system looks solid. The weather doesn't permit outdoor measurements now.

I have also re-read the thread about dipole tweeters. There are problems. A B&G Neo 3 doesn't go much lower that CD3.5 and Neo8PDR has worse highs. A pair of 25mm tweeters is maybe worth testing... Then I could reduce mid-tweeter ctc from 95 to 80mm and use lower xo. But I very much like the sound now!

Some thinking processes and distortion tests have guided me to push a little more to the lower limits of NE95 pair and Fountek NeoCD3.5. Middle xo is LR2 again at 800Hz and upper LR4 at 2500hz. Obviously the slopes ease the drivers enogh, There doesn't seem to be a rise in distortion. LR2 between mids gives much better (even) wide angle response than LR4. Lowered tweeter xo should give better vertical off-axis, but I didn't measure it today.

RT and EDT of my room - the effect of closing the light curtains kills the resonation at 2kHz.

It is now obvious to me that the 2kHz undulation I hear is very much this window resonation. These indoor tests don't tell the real behaviour of the speaker! Windows and furniture are rattling too! I haven't fixed the lower mid driver very well - it has vibrations around 100Hz. But overall the system looks solid. The weather doesn't permit outdoor measurements now.

I have also re-read the thread about dipole tweeters. There are problems. A B&G Neo 3 doesn't go much lower that CD3.5 and Neo8PDR has worse highs. A pair of 25mm tweeters is maybe worth testing... Then I could reduce mid-tweeter ctc from 95 to 80mm and use lower xo. But I very much like the sound now!

By lowering the crossover point you have better matched the CtC distance of the NE95's improving the acoustic phase angle. LR4 would may have attenuated the off axis too much. Have you nulled the ribbons impedance peak? Also on the NE95's and the low mid? Would help to reduce IMD in their pass bands.

I haven't done similar distortion test of any other speaker so far - I must get some control samples at same level! SPL level is not calibrated except the UMIK-1 cal file. Must be checked with another meter. The sweep sounded horrible and I just can't listen to music at same level (-20dB in receiver/preamp) for a long time.

I have prepared a 15-page powerpoint presentation of this project. If someone is interested, please send me PM and tell your email adress, and I will send a pdf copy to you!

About bass performance, I took some nearfield measurements and here you can see the options of LR2 and LR4 at 130Hz. -6dB in nearfiel is at 25Hz. 300ms room response start at 15Hz if we believe UMIK and REW! The bass channel of minidsp has Linkwitz Transform type peq at 40Hz, Q=1, -6dB (to avoid digital clipping) Driver is SEAS L26ROY in 25 liter sealed cabinet.